Abstract: To provide a work machine that can maintain the construction precision of semi-automatic control irrespective of excavation depths and differences in soil nature. A controller acquires soil-nature information on the basis of an operation command given to a work implement, a bucket-claw-tip position outputted from a bucket-position measuring device, and a drive load of the work implement outputted from a load measuring device; generates a soil-nature map on the basis of the bucket-claw-tip position, and the soil-nature information; calculates an estimated load that is an estimate of an excavation load on the basis of the soil-nature map and a bucket-claw-tip target position; and corrects the operation command in accordance with the estimated load.

Abstract: A controller mounted in a work machine limits a velocity at which a work device approaches a design surface to be equal to or lower than a predetermined limiting velocity in such a manner that the work machine is located above the design surface when an operation device is operated. The controller determines whether a work phase of the work device is compaction work on the basis of a posture of a bucket with respect to the design surface in a case in which the operation device instructs the work device to approach the design surface, and sets the limiting velocity when determining that the work phase of the work device is the compaction work to be higher than the limiting velocity when determining that the work phase of the work device is other than the compaction work.

Abstract: A work machine capable of assisting in an operator's operation to allow a work tool move along a design surface indicating a target shape of an object to be worked irrespectively of an angle of the design surface and a posture of a work implement is provided. A controller determines an excavation actuator in charge of an excavation action and determines an alignment actuator in charge of an alignment action for a work tool out of a plurality of actuators on the basis of the design surface set by a work execution target setting device and the posture of the work implement measured by a work implement posture/position measurement device, determines a target velocity of the excavation actuator on the basis of operation signals outputted from an operation device, and limits a target velocity of the alignment actuator in a direction in which the work tool approaches the design surface.

Abstract: A hydraulic work machine is provided which can improve the finishing accuracy in a horizontally leveling work, a slope face shaping work and so forth by preventing sudden acceleration of an arm when the excavation load decreases suddenly. The hydraulic work machine includes an arm velocity-control valve device 22 capable of adjusting a meter-out opening of the arm cylinder independently of a first arm directional control valve 23. A controller 100 is configured to control, when correcting and increasing an operation amount instructed by the first arm directional control valve, the arm velocity-control valve device to decrease the meter-out opening of the arm cylinder in response to the increase of load pressure of the arm cylinder.

Abstract: Target speeds of an arm cylinder and a boom cylinder are computed in response to a distance D between a bucket tip end and a target surface in such a manner that an operating range of a work device is limited on and above the target surface at a time of operating an operation device. A second flow control valve that supplies a hydraulic operating fluid from a second hydraulic pump to the boom cylinder is controlled on the basis of the target speed of the boom cylinder while a first flow control valve that supplies a hydraulic operating fluid from a first hydraulic pump to the arm cylinder and a third flow control valve that supplies the hydraulic operating fluid from the second hydraulic pump to the arm cylinder are controlled on the basis of the target speed of the arm cylinder.

Abstract: A controller (25) of the hydraulic excavator (1) includes a signal separation section (150) that separates each of target speed signals for a plurality of front members (8, 9, 10) into a low frequency component and a high frequency component, a high fluctuation target speed calculation section (143) that allocates the separated high frequency components preferentially to a front member having a relatively small inertial load to calculate high fluctuation target speeds individually for the plurality of front members, a high fluctuation target actuator speed calculation section (141c) that calculates high fluctuation target speeds individually for the plurality of actuators from the high fluctuation target speeds for the plurality of front members, a low fluctuation target actuator speed calculation section (141b) that calculates low fluctuation target speeds individually for the plurality of actuators from the low frequency components separated by the signal separation section, and an actuator controller (200)

Abstract: It is determined whether a velocity estimation model is established from an actual operating velocity Vr and a target operating velocity Vt of each of actuators 20A, 21A, and 22A; in a case in which the velocity estimation model is established, a dynamic center-of-gravity position of a hydraulic excavator 1 in a case in which each of the actuators 20A, 21A, and 22A is suddenly stopped from a driven state is predicted from an estimated operating velocity Ve; in a case in which the velocity estimation model is not established, the dynamic center-of-gravity position is predicted from the actual operating velocity Vr and it is determined whether to execute control intervention using the predicted dynamic center-of-gravity position; and in a case in which it is determined to execute the control intervention, the target operating velocity Vt is corrected in such a manner that each of the actuators 20A, 21A, and 22A slowly decelerate.

Abstract: An hydraulic excavator calculates an estimated excavation volume Va defined by a bucket claw tip position (first position) at an excavation start, a bucket claw tip position (second position) at an excavation end set in advance, a current landform, a first target surface, and a bucket width w. A second target surface is generated at a position superior to the first target surface when the estimated excavation volume Va exceeds a limit volume Vb; and the second target surface is generated at a position at which the excavation volume defined by the first position, the second position, the current landform, the second target surface, and the bucket width is closer to the limit volume Vb. The hydraulic actuators are controlled such that an operating range of a work implement is limited on the second target surface and to an area superior to the second target surface.

Abstract: Provided is a work machine with which an operator can easily perform semi-automatic excavating shaping work at an intended excavation velocity.

Abstract: A controller for a hydraulic excavator includes a first speed computation section that calculates a first speed of an arm cylinder from a value detected by an operation amount sensor; a second speed computation section that calculates a second speed from a value detected by a posture sensor and a third speed computation section calculates a third speed that is used as the speed of the arm cylinder in an actuator control section adapted to execute MC. The third speed computation section calculates the first speed as the third speed during the period between the detection of an input of operation for an arm by the operation amount sensor and predetermined time to, the third speed as a speed calculated from the first speed and the second speed during the period between t0 and time t1, and the second speed as the third speed at and after time t1.

Abstract: A hydraulic work machine is provided which can improve the finishing accuracy in a horizontally leveling work, a slope face shaping work and so forth by preventing sudden acceleration of an arm when the excavation load decreases suddenly. The hydraulic work machine includes an arm velocity-control valve device 22 capable of adjusting a meter-out opening of the arm cylinder independently of a first arm directional control valve 23. A controller 100 is configured to control, when correcting and increasing an operation amount instructed by the first arm directional control valve, the arm velocity-control valve device to decrease the meter-out opening of the arm cylinder in response to the increase of load pressure of the arm cylinder.

Abstract: Provided is a work machine equipped with a semi-automatic control for assisting operator's operation in works to excavate the ground to form a surface as designed, which work machine can assist operator's operation in compaction works to compact the ground to form a surface as designed. In a work machine 100 including a controller 25 having a semi-automatic control section 31 that corrects an operation amount indicated by an instruction given by operation devices 15L and 15R, the controller includes: a compaction determining section 52 that determines whether or not a work tool 7 is being pressed against a ground; and an actuator control correcting section 54 that further corrects an operation amount having been corrected by the semi-automatic control section, such that a force that the work tool applies to the ground increases if the work tool is determined by the compaction determining section as being pressed against the ground.

Abstract: Provided are a work point position computing section configured to compute the relative position of a work point set on a bucket with respect to an upper swing structure on the basis of posture information, a target surface setting section configured to set a target surface as a target of excavation work on the basis of design surface information, a primary operation determining section configured to determine which of operations of a boom and an arm is a primary operation as a main operation when the work point is moved along the target surface, and a recommended operation computing section configured to compute a recommended operation amount and a recommended operation direction of a secondary operation as another operation different from the primary operation in the operations of the boom and the arm according to an operation amount and an operation direction of the primary operation.